What features are found in all mollusks?

The characteristics of Mollusks are as follows: They have unsegmented soft body. They most have internal or external shell; they have a mantle, a fold in the body wall that secretes the hard protective shell, they have muscular foot and/or tentacles, they have a radula, a toothed structure used to grate food and they have two pairs of gills except in polmonate snails.